Comparison of PET, MRI, and CT with pathology in a proven case of Alzheimer's disease

Positron emission tomography (PET) with fluorodeoxyglucose (FDG), magnetic resonance imaging (MRI), and CT were carried out in a patient with Alzheimer's disease 16 months before he died. At autopsy, the gross appearance of the brain correlated with MRI and CT, which showed some regional atrophy. These were much less revealing than PET, which correlated with microscopic findings of neuronal loss and proliferation of glia. In areas of moderately impaired local cerebral metabolic rate of glucose, as revealed by reduced FDG uptake, there was some gliosis, primarily around the numerous senile plaques. In areas of severe metabolic impairment, there was a profound loss of neurons, extensive gliosis, and a diminished appearance of plaques. PET-FDG is a better measure of the severity of Alzheimer's disease than MRI or CT, because it reflects the degree of neuronal pathology.     

Nuclear magnetic resonance proton imaging of bone pathology

Thirty-two patients with diversified pathology were examined with a supraconductive NMR imager using spin echo with different TR and TE to obtain T1 and T2 weighted images. They included 20 tumors (12 primary, eight metastasis), six osteomyelitis, three fractures, two osteonecrosis, and one diffuse metabolic (Gaucher) disease. In all cases except for the stress fractures, the bone pathology was clearly visualized in spite of the normal lack of signal from the compact cortical bone. Nuclear magnetic resonance (NMR) imaging proved to be at least as sensitive as radionuclide scintigraphy but much more accurate than all other imaging procedures including computed tomography (CT) and angiography to assess the extension of the lesions, especially in tumors extended to soft tissue. This is due both to easy acquisition of sagittal and coronal sections and to different patterns of pathologic modifications of T1 and T2 which are beginning to be defined. It is hoped that more experience in clinical use of these patterns will help to discriminate between tumor extension and soft-tissue edema. We conclude that while radionuclide scintigraphy will probably remain the most sensitive and easy to perform screening test for bone pathology, NMR imaging, among noninvasive diagnostic procedures, appears to be at least as specific as CT. In addition, where the extension of the lesions is concerned, NMR imaging is much more informative than CT. In pathology of the spine, the easy visualization of the spinal cord should decrease the need for myelography.     

Crossed innervation of the superior rectus.

We studied two patients which showed a paralysis of the oculomotor nerve on one side and isolated paralysis of the superior rectus on the other side. On the side of oculomotor nerve paralysis, midbrain infarct extending from the paramedian tegmentum to crus cerebri was demonstrated in one case who showed no recovery, and a small lacuna in midbrain tegmentum in another one who showed complete recovery. On the side of isolated paralysis of the superior rectus, no lesion was demonstrated by CT and MRI, and no clinical signs of the involvement of fiber tracts or nuclei were evident in both cases. A unilateral lesion of oculomotor nerve nucleus caused a paralysis of the contralateral superior rectus.     

Effects of depleting central and peripheral adrenaline stores on blood pressure in stroke-prone spontaneously hypertensive rats

The potential role of adrenaline, both circulating and in the central nervous system, in the maintenance of high blood pressure was examined in stroke-prone spontaneously hypertensive rats (SHRSP). alpha-Monofluoromethyldopa, a long-lasting inhibitor of dopa decarboxylase, was used to induce rapid depletion of central and peripheral catecholamine stores. Subsequent inhibition of phenylethanolamine-N-methyltransferase (PNMT) allowed the gradual restoration of dopamine and noradrenaline but not adrenaline, resulting in a greater relative depletion of adrenaline. Adrenaline was almost totally depleted in the circulation and peripheral tissues. The resting level of blood pressure, however, was unaffected, excepting after administration of a vasopressin (AVP) antagonist. Moreover, there was no reduction in the magnitude of acute pressor responses to electrical stimulation of the rostral ventrolateral medulla oblongata (C1 area), despite extensive loss of adrenaline from the brainstem and spinal cord. The results suggest that adrenaline contributes to the resting level of blood pressure but that its loss can be offset by the pressor activity of AVP. Thus neither central nor peripheral adrenaline stores appear to be essential for the maintenance of hypertension or for centrally-evoked vasoconstriction in adult SHRSP.     

Changes in serum amino acids in total parenteral nutrition supported patients with intra abdominal infection

Serum aminogram changes were prospectively studied in 95 patients with enteric fistula and intraabdominal infection who was under total parenteral nutrition (TPN) therapy with Anfuming 14s. In patients with sepsis and starvation, the aminogram showed remarkably low total free amino acids before TPN therapy. In 81 survivors, free amino acids increased gradually to normal in 2 weeks after use of TPN and in 14 dead cases increased rapidly to a significantly higher peak at terminal stage. Both in survivors and nonsurvivors, phenylalanine level remained high during the study. In response to infection, proline was also elevated but to a lesser degree; the ratio of branched chain amino acid (BCAA) to aromatic amino acid (AAA) was lower than normal and the decrease of arginine was parallel to the severity of infection. We conclude that the ideal amino acids preparation for the starvated and septic patients should be high in BCAA and arginine but low in phenylalanine, administration of inappropriate exogenous amino acids in decompensated metabolic septic patients may bring about more harm than benefit, and in septic patients that the levels of serum phenylalanine and proline are elevated persistently along with the decrease of arginine level is a useful prognostic indication.     

Zinc, calcium, and magnesium metabolism: effects on plasmacytomas in Balb/c mice

The effects of different amounts of dietary zinc on the Zn absorption rate and on Zn, calcium and magnesium concentrations in tissues of MOPC 104E tumor-bearing Balb/c mice were determined. The Zn absorption rate was inversely related to the amounts of Zn in their diets and was lower than that of nontumor-bearing control mice fed a laboratory mice chow. Zn concentrations of tumor-bearing mice were also low compared with control mice but tumor Zn concentrations, regardless of the concentrations of Zn in the diets, were higher than those of normal tissues of the host other than the pancreas. Ca concentrations in tumor and tissues of tumor-bearing mice were higher than in control animals but Mg concentrations in tissues of tumor-bearing mice appeared to be similar to those of control mice. Results suggest that tumor-bearing mice have a lower intestinal Zn absorption capacity and a higher Zn uptake rate causing other tissues to become hypozincemic and hypercalcemic.     

Effect of morphine on the mechanical activity of common bile duct isolated from the guinea pig

The contractile response of isolated guinea pigs common bile ducts (CBD) to transmural electrical stimulation and the effects of morphine and naloxone was studied. Contractile responses increased as a function of stimulus frequency. In the absence of naloxone morphine inhibited the contractile response to electrical stimulation in a dose-dependent manner. Naloxone prevented the inhibitory effect of morphine on the contractile response to electrical stimulation. We conclude that smooth muscle of the CBD in guinea pig is functional and can contribute to biliary motility, and that opiate receptors exist in nerve elements in the CBD.     

A nationwide survey on transient hyperammonemia in newborn infants in Japan: prognosis of life and neurological outcome.

A nationwide survey of transient hyperammonemia in newborns was carried out in Japan. A total of 18 patients, consisting of 12 male and 6 female infants, were reported from 11 facilities. These neonates exhibited hyperammonemia with plasma ammonia levels in the range from 124 to 6256 micrograms/dl. Four newborn infants of the 18 died in the neonatal period, and an additional one died in the early infancy. Among the 13 infants who were alive at the time of this survey, 6 had neurological sequelae, including mental retardation, spastic quadriplegia and epilepsy. The multivariate analysis revealed that the Apgar score at 1 minute, peak plasma ammonia concentration, birth weight and sex were significant factors affecting the prognosis of life.